Ink-ribbon vibrator mechanism in typewriters



Aug. 13, 1929. P. KAPP ER INK RIBBON VIBRATOR MECHANISM IN TYPEWRITERS Filed Dec. 23 1927 A 2 Sheets-Sheet 1 for ler

Aug. 13, 1929. KA 1,724,485

INK RIBBON VIBRATOR MECHANISM IN TYPEWRITERS Filed Dec. 25, 1927 2 Sheets-Sheet 2 Patented Aug. 13, 1922,

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PAUL KEPPLER, OF DRES'DEN, GERMANY.

INK-RIBBON VIBBATGE MECHANISM IN TYPEVIRITERS.'

Application filed December 28, 1927, Serial No. 242,163, and .in Germany January 6', 1927.

This invention relates to the ink ribbon vibrator mechanism of typewriters of the kind employing two-colour or multi-colour ink ribbons. In such typewriters, it IS necessary that the vibrator mechanism should work reliably and accurately because the breadth of each colour zone of the ink ribbon only exceeds the type height by a small amount, so that any slight fault 1n the v1- bration of the ink ribbon may bring part of two different colour Zones beneath the type.

According to the present invention, the ink ribbon vibrator is driven by a rocking member comprising two limbs spaced apart and connected together by a yoke piece, the rocking member being pivotally mounted at each side on trunnions supported by the two arms of a bracket which supports the v1- brator mechanism. The two limbs of the rocking member are adapted by means t pins and slots to alternately cooperate with an intermediate actuating member slidable p011. and mounted to rock upon a spindle supported by saldframe and connected to a setting knob or like device, sald pins and slots being so positioned that thestroke 1mparted by the actuating member to the ribbon vibrator through the rocking member is greater when one pin is engaged than when the other pin is engaged, so that variation of the ribbon vibration may be efi'ected by displacing the actuating member laterally. The actuating member IS IOClKECl by the key action through the un versal bar against the action of a returningsprmg, adjustable stops being provided to limit the movement of the ribbon vibrator and the associated rocking and actuating members. The actuating member may be adapted to be moved into an intermediate position, out of engagement with the rocking member, so as to render the ribbon vibrator inoperatlve. This construction has the advantage that, not only is the rocking member firmly supported, thereby resulting in greater durability and reliability and also ensuring effective control of the ribbon vibrator, but by slightly twisting the two limbs of the rocking member relatively to one another or by adjusting said stops, the vibrator can be readily adjusted to cause each colour zone of the ribbon to be brought into the correct writing position.

The bracket which supports the mechanism may be detachably fitted to the carriage of the typewriter, so that the vibrator mechanism can be removed from or replaced in the machine as a self-contained unit, without having to remove any other parts.

In order that the invention may be. more clearly understood, reference is hereinafter made to the accompanying explanatory drawings whereon:

Fig. 1 is a schematic sectional View of the typewriter and Fig. 2 is a perspective view of the vibrator mechanism.

In the constructional example illustrated, case shift is effected by upward displacement of the carriage 17 in any known manner. The actuation of any one of the bank of keys 1 to 4: causes the type bars 7 to strike the platen 8, the type bars 7 being actuated through the levers 5 and connecting rods 6. A projection 9 on the levers 5 also actuates the universal bar 12 which swings about a shaft 13, thereby oscillating a lever 14 fixed on the shaft 13 in the direction of the arrow shown in Fig. 1. v The lever 14 bears upon the edge of a plate 35 carried by an arm 15 which is freely mounted on a spindle 16 supportedin a bracket 19. The spindle 16 is axially slidable in the bracket or frame 19 which is fixed to the carriage 17, the spindle 16 being moved axially by connection through a bent plate 16" to a knob .20. Accidental displacement of the spindle 16 is prevented by the provision of a spring detent 21 on the plate 16 whichengages notches 22 in an extension 19 of the bracket 19. Adjustably fixed on thespindle 16 is a collar 23 and a spring 2 l on the spindle 16 abuts against the collar 23 and is connected to the arm 15 and collar 23 so as to serve to rock the arm 15 in such manner as to hold the plate 35 against the lever lei. Connected by a cross bar 15 to the arm 15 is a second arm 15 also freely mounted on the spindle 16. The spring 2% in compression between the collar 23 and arm 15 causes the arm 15 to abut against the collar 23 and the unit formed by the arms 15 and 15 and cross bar 15 thus moves with the spindle 16 when the latter is axially moved. A yoke 29 having arms 29 and 29 is pivotally mounted in the bracket 19 on studs 28 and has pins 26 and 27, one or other of which can be brought into engagement with corresponding slots 30 and 31 in the arms 15 and 15 according to the position of the latter. The pins 26 and 27 are at different distances from the pivot pins or studs 28 so that they transmit different angular movements to the yoke 29 for the same angular travel of theplate 35 and thus effect varied vibration of the ribbon vibrator 32 which is knuckle-jointed at 29 to the yoke 29. Owing to the rocking movement of the arms and 15 slight relative sliding movement occurs between the pins 26 and 27 and the slots 30 and 31. Therefore, and in order also to compensate for inaccuracies in the manufacture of the parts, the apertures 30 and 31 are elongated or in the form of slots to receive the pins 26 and 27.

When the knob is in the left-hand p0sition shown in Fig. 2, that is to say, when the slot is in engagement with the pin 26, the depression of a key will cause the vibrator 32 to describe its smaller movement so that the upper or black zone of the ink ribbon will be brought in front of the printing point. If the knob 20 is moved to the right, the slot 31 will engage the pin 27 and thus cause the vibrator 32 to describe its larger movement, thereby bringing the lower (red) ribbon zone in front of the printing point.

The knob 20 may also be set at an intermediate position in which neither of the pins 26 and 27 will engage the slots 30 and 31 and in this position no vibratory movement will be transmitted to the vibrator 32, thereby rendering the ink ribbon inoperative (for stencil work).

The two widely spaced bearings 28 for the yoke 29 provide a reliable and dependable mounting for the yoke 29 as well as for the vibrator 32 which is guided at its lower end by the knuckle-joint 29 and at its upper end by lugs 32 engaging the inner end edges of the spaced wings of a line scale or indicator 40.

It is import-ant that the limitation of the vibratory movement of the ink ribbon should be reliable and for the purpose an adjustable stop 33 is provided on the bracket 19, against which the arm 15 is adapted to abut at the end of its rocking movement in any position of the knob 20. The position of rest is determined by an adjustable stop 34 on the bracket 19 against which the yoke arm 29 isadapted to rest. By forcibly twisting one of the two limbs 29 and 29 which carry the pins 26 and 27 relative to the other, the limits of movement of both ink ribbon zones can be sufficiently accurately and very conveniently adjusted.

lVhen the paper carriage support 17 is displaced to bring the lower case of type (or capital letters) into operative position in relation to the platen 3, the whole of the vibrator mechanism moves with the carriage, thus eliminating any differences of travel which would otherwise result therefrom.

' During the case-shiftmovement of the carriage, the plate 35 rides along the edge 36 of the lever 14- which is inclined in the same direction as the direction in which the carriage moves during the case-shift movement. The edge of the plate 35 is made sutiiciently long to ensure that it will always remain in contact with the lever 14 in any position of the knob 20.

Claims:

1. Ink ribbon vibrator mechanism for typewriters comprising a ribbon vibrator, a rocking member articulated thereto and having two limbs spaced apart and connected by a yoke, a bracket upon which said rocking member is pivotally mounted at each side, an actuating member slidable between said limbs, a spindle mounted in said bracket and supporting said actuating mem ber, pin and slot connections arranged at different distances from the pivotal axis of t 1e rocking member for alternately connecting said actuating member with one or the other of said limbs of the rocking member on reverse sliding movements of said actuating member for thereby varying the stroke of the rocking member, means for sliding said actuating member and means, operated by the key action of the typewriter, for rocking said actuating member.

2. Ink ribbon vibrator mechanism as speci fied in claim 1 in which said actuating member comprises a pair of connected arms, each provided with a slot, and in which the limbs of the rocking member carry the pins to engage said slots.

3. Ink ribbon vibrator mechanism as specified in claim 1 in which each limb of the rocking member has a pin adapted to cooperate with a slot in the actuating member, said pins being at different distances from the pivotal axis of the rocking member.

l. Ink ribbon vibrator mechanism for typewriters comprising a ribbon vibrator, a member articulated to said vibrator, a pair of limbs one at each end of said member, a pair of brackets, each of which supports a trunnion for one of said limbs, a pin projecting from each limb but at different distances from the trunnions, a pair of connected slotted arms adapted to alternately engage said pins, a spindle supported by said brackets and upon which said arms are freely mounted, a collar forming an abutment for one of said arms, a coil spring in compression between said collar and the other arm and attached at its ends thereto, means for axially moving said spindle, and means, operated by the key action of the typewriter, for rocking said arms against the action of said spring.

5. Ink ribbon vibrator mechanism as specified in claim 1 having adjustable stops for limiting the stroke of the rocking member and actuating member in any of their relative positions .of adjustment.

6. Ink ribbon vibrator mechanism as claimed in claim 1 in which the bracket is U-shaped and its arms form the supports for the rocker member and the actuating member spindle, while its body portion connecting said arms is detachably mounted on the platen carriage support of the type- Writer.

7. The combination with ink ribbon vibrator mechanism as claimed in claim 1 of a line scale comprising spaced wings mounted upon said bracket, between which the ribbon vibrator is fitted to slide, and guiding means on the vibrator engaging the inner edges of said wings.

8. Ink ribbon vibrator mechanism as specified in claim 1 wherein the actuating member is provided with spaced arms formed with the slots of the pin and slot connections, one of said arms having a horizontal bearing face engaged by an element of the key-operated mechanism of the typewriter.

PAUL KAPPLER. 

